UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/62.0.3202.94 Safari/537.36

Steps to reproduce the problem:
1. Notice that the debugger correctly breaks on this uncaught exception in this code pen: https://codepen.io/yaaang/pen/pdmWvp

Code here:

function sleep() {
  return new Promise(resolve => setTimeout(resolve, 1));
}
async function thrower() {
  await sleep();
  throw '!';
}
thrower();

2. Try running this one now: https://codepen.io/yaaang/pen/OOYxyb

Code:

...
(async function() {
  await thrower();
})();

What is the expected behavior?
Debugger should break. It does so for outermost async call only. Firefox does support this.

What went wrong?
Debugger did not break.

Did this work before? N/A 

Chrome version: 62.0.3202.94  Channel: n/a
OS Version: OS X 10.10.5
Flash Version: 

This would be a major boon to debugging productivity.